Binocular Review - Optical Design

Binocular Review - Optical Design
by Joe "Woods Goods and Stuff"

Binocular Review - Optical Design

Galilean binoculars

Almost from the invention of the telescope in the 17th century the advantages of mounting two of them side by side for binocular vision seems to have been explored. Most early binoculars used Galilean optics; that is they used a convex objective and a concave eyepiece lens. The Galilean design has the advantage of presenting an erect image but has a narrow field of view and is not capable of very high magnification. This type of construction is still used in very cheap models and in "opera glasses" or theater glasses.

Porro prism binoculars

Named after Italian optician Ignazio Porro who patented this image erecting system in 1854 and later refined by makers like Carl Zeiss in the 1890's, binoculars of this type use a Porro prism in a double prism Z-shaped configuration to erect the image. This feature results in binoculars that are wide, with objective lenses that are well separated but offset from the eyepieces. Porro prism designs have the added benefit of folding the optical path so that the physical length of the binoculars is less than the focal length of the objective and wider spacing of the objectives gives better sensation of depth.

Roof prism binoculars

Binoculars using Roof prisms may have appeared as early as the 1880s in a design by Achille Victor Emile Daubresse. Most roof prism binoculars use either the Abbe-Koenig prism (named after Ernst Karl Abbe and Albert Koenig and patented by Carl Zeiss in 1905) or Schmidt-Pechan prism (invented in 1899) designs to erect the image and fold the optical path. They are narrower, more compact, and more expensive than those that use Porro prisms. They have objective lenses that are approximately in line with the eyepieces.

Porro vs. Roof prisms

Aside from the difference in price and portability noted above these two designs have effects on reflections and brightness. Porro-prism binoculars will inherently produce an intrinsically brighter image than roof-prism binoculars of the same magnification, objective size, and optical quality, as less light is absorbed along the optical path. However, as of 2005, the optical quality of the best roof-prism binoculars with up-to-date coating processes as used in Schmidt-Pechan models is comparable with the best Porro glasses, and it appears that roof prisms will dominate the market for high-quality portable binoculars in spite of their higher price.The major European optical manufacturers (Leica, Zeiss, Swarovski) have discontinued their Porro lines; Japanese manufacturers (Nikon, Fujinon, etc.) may follow suit.

Binocular Review - Optical Design
by Joe "Woods Goods and Stuff"

Binocular Review - Spotting Scopes

Binocular Review - Spotting Scopes
by Joe "Woods Goods and Stuff"

A spotting scope is a portable telescope, optimized for the observation of terrestrial objects. The magnification of a spotting scope is typically on the order of 20X to 60X. Other common features include:

• somewhat "rugged" or rubber-armored design
• convenient mounting for attaching to a tripod
• ergonomically designed and located knob for focus control
• tethered elastomeric lens cap
• a range of eyepieces to give different magnifications, or a variable "zoom" eyepiece to give a range of magnifications (e.g. 20-60X)

The light gathering power of a spotting scope is determined by the width of the objective lens, typically between 55 and 80 mm. All else being equal, the larger the objective, the more heavy and expensive the telescope.

There are three types of scope: "straight-through" (the eyepiece is on the same axis as the body of the scope), "angled" (the eyepiece is at an angle of about 45 degrees to the body of the scope), and, rarely, a more complex, shoulder-mounted design. Straight-through scopes are easier to use from, say, inside a car, while angled scopes are more comfortable for tall people and more easily shared by people of different heights.

The choice of the eyepiece lens determines the overall magnification. The best magnification is decided by a number of factors. Magnifications of less than 20X are unusual, as (much cheaper and lighter) binoculars or monoculars can provide this. Magnifications of more than 60X lead to poorer brightness and, even on a tripod, shake can be a problem. The field of view is also limited.

Usually for birdwatching, 20X or 30X is favored. This gives a good field of view and a bright image. Amongst aircraft spotters the term "pole" is used as a shorthand expression meaning telescope. The related verb "to pole-off" therefore means reading some identification marks of an airplane by using a telescope. Other users might employ the same slang term.

Binocular Review - Spotting Scopes
by Joe "Woods Goods and Stuff"

Binocular Review - Best Binoculars

Binocular Review - Best Binoculars
by Joe "Woods Goods and Stuff"

Best Binoculars - Brunton Binoculars

Brunton Binoculars feature high quality optics and rugged constraction. Most of Brunton Binoculars are waterproof and have multi-coated optics. Every Brunton Binocular comes with complementary Brunton Binocular Accessories (such as a case, a strap, even a tripod adapter with selected models). Brunton Binoculars - a generation born from innovation. The intrigue surrounding the Best Binoculars on earth continues to grow exponentially, while the entire line of rugged Brunton Optics continue to set the bar for sharp views and stellar performance.

You can choose from three lines of high-end Brunton Binoculars that match your passion:

• Brunton Epoch Binoculars - revolutionary in status, simply the best binoculars in the world.
• Brunton Eterna Binoculars - rugged and remarkable, see brighter than ever before.
• Brunton Echo Binoculars - affordability with unprecedented Brunton quality.

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Binocular Review - Best Binoculars
by Joe "Woods Goods and Stuff"

Binocular Review - Maintenance Tips

Binocular Review by Joe "Woods Goods and Stuff"

Maintenance Tips

If you're deciding to buy a brand new pair of binoculars in the near future not only do you need to learn what kind of binoculars will suit you best but you also should know the proper binocular maintenance to keep your optics working well for years to come. Just because your binoculars are made of durable high quality materials and craftsmanship doesn't mean you should abuse them.

A good place to start with is the accessories associated with binoculars. Most commonly, the binocular strap, it should always maintain around your neck as a high percentage of damage is caused when binoculars are dropped and banged up. Make sure the clips and locking devices are securely fastened, as you don't want to assume and end up with an accident. If you are physically participating in any activity that could cause your binoculars to get caught or trapped in something, be sure to remove them from your neck and store them securely to avoid any possible injuries or strangulation.

A properly fit carrying case with padding should be the only storage home for your new binoculars. Anytime the binocular is not is use, take a moment to put it away while enroute to your next hunting trip, hiking adventure, bird watching escape and star gazing hill.

Another simple way to maintain your lenses is with the eyecups, if your keeping your binoculars on your neck it's a good idea to put the lens cups back on to keep any dirt and dust off of the lenses. Also, do not leave your binoculars in direct sunlight as the increase in heat can possibly cause damage internally and externally.

When cleaning the binocular lenses follow manufacturer lens maintenance guidelines. Never, wipe or rub dry lenses with dirt, dust or debris on it as that will scratch and damage the surface leaving you with a less than clear image. First, dust off any loose debris, and then with a proper maintenance cleaning solution or lens pen moisten the surface. Use a soft, suitable cleaning cloth to wipe residual oil and dirt away.

It is also a good idea to wipe down your binoculars with a damp cloth to remove any oils from your skin as well as any dirt or debris that may have accumulated on the binoculars themselves before placing them away in storage. This will keep your binoculars looking good as new every time you take them out for that next amazing site to see.

Binocular Review by Joe "Woods Goods and Stuff"

Binocular Review - How to focus Binoculars

Binocular Review by Joe "Woods Goods and Stuff"

How to focus Binoculars

It is surprising how many people do not know how to focus binoculars correctly. There are two common focusing systems used in binoculars.

The first is individual eyepiece focus. This system is simple to understand, and easy to manufacture. It also lends itself well to sealed optical tubes, and thus is usually the focusing system used for waterproof binoculars. Individual eyepiece focus means that to focus the binoculars to your eyes, you simply focus the left eyepiece to your left eye and the right eyepiece to your right eye. There is no centrally located focusing mechanism. It is done like this. Look at something in the distance. Close the right eye (or cover the front of the right binocular), and focus the left eyepiece to your left eye. Close the left eye (or cover the front of the left binocular), and focus the right eyepiece to your right eye. You are finished, until you need to look at something at a different distance, in which case you need to repeat the process.

Because individual eyepiece focus is time-consuming, center focus is more common. Unfortunately, very few people understand how to correctly use center focus binoculars. Here is how it is done. Aim your binoculars at something in the distance. Close the right eye (or cover the front of the right tube), and focus the left side of the binocular to your left eye using the center focus control, which is concentric with the pivot shaft between the binoculars. (Note: the left eyepiece itself does not focus on center focus binoculars.) Next, close your left eye (or cover the front of the left tube), and focus the right eyepiece to your right eye. DO NOT touch the center focus control while you are focusing the right eyepiece to your right eye. Now you are finished. What you have just done is adjust the binoculars for your individual eyes. (Practically everybody's left and right eyes are different.) From now on, you only need to adjust the center focus control when you look at things at different distances. Center focus is faster and easier to use than individual eyepiece focus, once you have initially set the binoculars for your eyes.


Binocular Review by Joe "Woods Goods and Stuff"

Binocular Review - See Your Game From Far Away

Binocular Review by Joe "Woods Goods and Stuff"

See Your Game From Far Away

There are a number of features available on hunting binoculars to consider choosing when trying to make a purchase as there is a big difference between a pair of binoculars used for magnify targets for hunting and those used for birding. While all binoculars magnify the object being viewed, the specific features chosen will be dependent upon whether used for hunting, birding, or some other activity. Some people mistakenly believe that there is little difference between a pair of binoculars made for birding and a pair made for hunting, the truth is that these are two very different kinds of binocular and each has advantages and features that make it ideal for one activity or the other. In order to understand the difference, you have to know the basic optical features of a pair of binoculars.

Binocular Review by Joe "Woods Goods and Stuff"

Binocular Review - Numbers (They Do Matter)

Binocular Review by Joe "Woods Goods and Stuff"

Numbers - They Do Matter

Any hunting binoculars review should begin with a basic explanation of what numbers like 8 X 25 mean to the optics of those binoculars. The number on the left is the magnification made possible by the optics of the binoculars. So, an 8 on the left is how many times the binoculars magnify that bird you are looking at through the optical system. The number on the right is known in the optical world as the objective lens diameter. Basically, this is the size of your lens and it is measured in millimeters and it is very important to your optics. In the world of the hunting binocular, the larger the objective diameter, the better – the same also happens to be true for the binoculars used for birding as well.

The reason you want to go hunting for birds or other game with a pair of binoculars that have a larger objective diameter is because they can be used in low-light conditions such as dusk or dawn—times when most bird hunting occurs and necessary to take into account when designing an optics system. The larger the lens, the brighter the bird will be in the optical system. Now some compact binoculars do have a specialized coating on the lens which enhances the optics and actually helps capture more sunlight. But, all things being equal, the hunter will want to go with a larger lens and the enhanced optics that go with it to see birds and other game as clearly as possible.

Binocular Review by Joe "Woods Goods and Stuff"